12 Dead in Colorado Theater Shooting

President Obama: "We are committed to bringing whoever was responsible to justice, ensuring the safety of our people and caring for those who have been wounded." Plus: The suspect has been identified as 24-year-old James Holmes.

Updated 10:55 a.m. EDT: President Barack Obama canceled his second campaign stop after the Aurora, Colo., mass shooting, CNN reports. He issued the following statement:

Michelle and I are shocked and saddened by the horrific and tragic shooting in Colorado. Federal and local law enforcement are still responding, and my Administration will do everything that we can to support the people of Aurora in this extraordinarily difficult time. We are committed to bringing whoever was responsible to justice, ensuring the safety of our people, and caring for those who have been wounded. As we do when confronted by moments of darkness and challenge, we must now come together as one American family. All of us must have the people of Aurora in our thoughts and prayers as they confront the loss of family, friends, and neighbors, and we must stand together with them in the challenging hours and days to come.

Updated 10:41 a.m. EDT: Federal authorities say that the suspect in the mass shooting is 24-year-old James Holmes, ABC News reports. A California woman who identified herself as his mother told ABC that her son was likely the culprit, saying, "You have the right person."

Earlier:

In Colorado's worst mass shooting since the Columbine High School massacre in 1999, a gunman wearing a gas mask set off an unknown gas and fired into a Aurora movie theater at a midnight opening of the The Dark Knight Rises early Friday morning, killing 12 people and injuring at least 50 others, the Washington Post reports:

Moviegoers didn’t know what was happening and some thought the attack was part of the show. Then they saw a silhouette of a person in the smoke at the front of the theater near the screen, pointing a gun at the crowd ...

Some of those injured are children, including a 3-month-old infant who was shot ...

The suspect was taken into custody, but no name was released. Oates said there's no evidence of any other attackers. There was also no immediate word of any motive.

President Barack Obama said he was saddened by the "horrific and tragic shooting," pledging that his administration was "committed to bringing whoever was responsible to justice, ensuring the safety of our people, and caring for those who have been wounded."